Steep Steps, for bass clarinet, plays the timbral angle for humor, staccato Raymond-Scott machinery in the bass against the unlikely espressivo of the instrument's treble, ending with a big-band saxophone-like wail of clarino; Brent Besner hit it all with character and flair.

But Mr. Serkin was at his best in the group of slow variations near the end, particularly the almost operatic Andante, sempre cantabile, and the Largo, molto espressivo, where his ruminative account recalled his flexible touch in the contemporary works in the first half of the program.